They're parodying NFTs not Olive Garden. Same scenario as Penny Arcade parodying video games with the unrelated Strawberry Shortcake property.

They are selling NFTs. They are making money, albeit not a lot, on the back of the goodwill of the Olive Garden brand. I think this is distinct from true parody say paying to watch a comedian who makes a joke about Olive Garden, or a free site that makes a joke about them.

If I paint a picture of an Olive Garden restaurant and sell it, is that infringement?

That seems more or less identical to the conceit here.

If you sell it on paintingsofolivegarden.com then maybe. The domain name implies association.

IANAL;IANYL

Didn't someone get away with a fake Starbucks because they were parodying parody law not Starbucks?

“ Starbucks did not pursue legal action, although it did note to the press that it was "evaluating" the possibility while reinforcing that the "Starbucks" name is a protected trademark. Upon the episode's broadcast, it was acclaimed by television critics.”

The store only lasted a few days. Who knows what would’ve happened otherwise.

https://en.m.wikipedia.org/wiki/Dumb_Starbucks

I imagine Olive Garden similarly wouldn't mind this website, but who knows. Maybe they'll take it down because they take it seriously and want in on the profits?

Does parody/fair use apply to trademarks? Genuine question, I don't know myself